They ignore questions about why he's gone abroad to get treatment and how much it's costing taxpayers.

But ten days becomes seven weeks. Canadians only ever see the head of their government in stage-managed photographs published on Twitter.

Senior government figures who travelled to London return to Canada and unanimously insist the prime minister is in top form and all use the same phrase — "hale and hearty."

Rumours abound

None of this happened with Trudeau, of course. But it's exactly what happened with Nigerian President Muhammadu Buhari.

He left Nigeria in mid-January, with the country deep in recession and famine warnings in parts of the northeast.

His spokespeople in the capital Abuja insisted all is fine and the 74-year-old just needed some rest.

But the reassurances proved increasingly ineffective as rumours swirled, particularly on social media.

On Friday, Buhari went some way to disproving at least two of the theories — that he was dead or in a coma — by returning to Nigeria.

A Nigerian air force plane touched down at 7:40 a.m. in the northern city of Kaduna, as Abuja airport is closed for at least six weeks to repair the runway — work that was supposed to have been done 15 years ago.

Buhari was ferried by helicopter back to the presidential villa, Aso Rock, in Abuja, where he was met by his deputy, Vice-President Yemi Osinbajo, and senior officials.

Ordinarily, that would be the end of the matter. But things are never quite so straightforward in Nigeria.

Buhari said he "couldn't recall being so sick" and revealed he'd had a blood transfusion, but offered no more detail.

He also said he wasn't resuming his position immediately and Osinbajo would continue as acting president while he had some more rest.

That news sparked further confusion — and presumably a check of the constitution by Buhari's team, who later revealed a formal letter will be written on Monday to inform parliament that Buhari is officially back in charge.

Until that happens, the rumours are likely to continue spreading.

'Exacerbate instability'

Why does all this matter?

Nigeria is Africa's most populous nation, a leading oil producer and widely viewed as the powerhouse of West Africa. Political instability in Nigeria bodes well for no one.

Elizabeth Donnelly, deputy head of the Africa program at London's Chatham House think-tank, believes the current economic, security and political contexts in Nigeria all help explain why Buhari's team hasn't provided any details about his health.

"Nigeria is under severe economic strain and is managing multiple security threats or local violent conflicts," she told CBC News. "I suspect the assessment by advisers was that suggesting the president was ill and weakened would exacerbate instability in some places and cause uncertainty, which would affect the economy."

Nor would his advisers want to "feed further factionalism" and potential challengers, she said.

History lesson

There's also the fear of history repeating itself. In late 2009, Nigerian President Musa Yar'Adua went to Saudi Arabia for medical treatment and was never seen in public again. His death was officially declared in May 2010.

It left a dangerous power vacuum in a country where there have been six successful military coups since independence from Britain in 1960.

Many Nigerians fear another Yar'Adua scenario with Buhari. But Donnelly believes this situation is different, particularly since Buhari officially made Osinbajo acting president before he left for London.

"That the acting president will continue in this role sends a clear signal to Nigerians of what is going on," she said. "So although messaging — denial for much of the time — around the circumstances of the president's absence echo that time to some degree, the process is being managed differently."

The cause of Buhari's illness will likely remain a mystery, but for now, Nigeria's missing president is back and resting.